5033727 JOHNSON VALVE, IAC

Perform this procedure under conditions that are identical to the conditions that exist when the fault occurs. Typically, faults with the injector solenoid occur when the engine is warmed up and/or when the engine is under vibration (heavy loads).These engines have Electronic Unit Injectors (EUI). The ECM sends a pulse to each injector solenoid. The pulse is sent at the correct time and at the correct duration for a given engine load and speed. The solenoid is mounted on top of the fuel injector body.An electrical fault can prevent the electronic unit injector from operating. An open or short circuit in the ECM that is unique to one electronic unit injector will prevent that electronic unit injector from operating. An open or short circuit in common wiring within the ECM can prevent the two electronic unit injectors that share that common wiring from operating.If an open circuit is detected in the solenoid circuit, a diagnostic code is generated. The ECM continues to try to fire the injector. If a short circuit is detected, a diagnostic code is generated. The ECM will periodically try to fire the injector. If the short circuit remains, this sequence of events will be repeated until the fault is corrected."Injector Solenoid Test"Use the "Injector Solenoid Test"to diagnose an open or short circuit diagnostic code while the engine is not running. The "Injector Solenoid Test" will send a signal to each solenoid. The electronic service tool will indicate the status of the solenoid as "OK", "Open", or "Short".
Electrical Shock Hazard. The electronic unit injectors use DC voltage. The ECM sends this voltage to the electronic unit injectors. Do not come in contact with the harness connector for the electronic unit injectors while the engine is operating. Failure to follow this instruction could result in personal injury or death.
During the following procedure, refer to the electrical schematic for the application.Complete the procedure in the order in which the steps are listed.
Table 2
Troubleshooting Test Steps Values Results
1. Inspect Electrical Connectors and Wiring
A. Turn the keyswitch to the OFF position. A strong electrical shock hazard is present if the keyswitch is not turned OFF.
B. Thoroughly inspect the connectors at the cylinder head. Refer to Troubleshooting, "Electrical Connectors - Inspect" for details.
C. Perform a 45 N (10 lb) pull test on each of the wires in the ECM connector that are associated with injector solenoids.
D. Check the screw for the ECM connector for the correct torque of 6 N m (53 lb in).
E. Check the harness and wiring for abrasion and for pinch points from the injectors to the ECM.
Loose connection or damaged wire
Result: There is a fault in a connector or the wiring.
Repair: Repair any faulty connectors or replace the wiring harness. Ensure that all of the seals are properly in place and ensure that the connectors are correctly coupled.
Use the electronic service tool to clear all logged diagnostic codes and verify that the repair eliminates the fault.
Result: All connectors, pins, and sockets are correctly coupled and/or inserted. The harness is free of corrosion, abrasion, and pinch points.
Proceed to Test Step 2.
2. Use the "Injector Solenoid Test"
A. Start the engine.
B. Allow the engine to warm up to the normal operating temperature.
C. Stop the engine.
D. Turn the keyswitch to the ON position.
E. Access the "Injector Solenoid Test" by accessing the following display screens in order:
"Diagnostics"
"Diagnostic Tests"
"Injector Solenoid Test"
F. Activate the test.
Note: Do not confuse the "Injector Solenoid Test" with the "Cylinder Cutout Test". The "Cylinder Cutout Test" is used to shut off fuel to a specific cylinder while the engine is running. The "Injector Solenoid Test" is used to actuate the injector solenoids while the engine is not running.
"OK", "OPEN", or "SHORT"
Result: All cylinders indicate "OK". There is not an electronic fault with the injectors at this time.
Use the electronic service tool to clear all logged diagnostic codes. Return the engine to service.
Result: "OPEN"
Note the cylinders that indicate "OPEN".
Proceed to Test Step 3.
Result: "SHORT"
Note the cylinders that indicate "SHORT".
Proceed to Test Step 4.
3. Check the Harness between the ECM and the Cylinder Head for an Open Circuit
A. Turn the keyswitch to the OFF position. A strong electrical shock hazard is present if the keyswitch is not turned OFF.
B. Disconnect the connector for the suspect injector from the cylinder head.